Scientists publish 'navigation maps' for human genome

LONDON (Reuters) - A large international team of scientists
has built the clearest picture yet of how human genes are
regulated in the vast array of cell types in the body - work
that should help researchers target genes linked to disease.

In two major studies published in the journal Nature, the
consortium mapped how a network of switches, built into human
DNA, controls where and when genes are turned on and off.

The three-year long project, called FANTOM5 and led by the
RIKEN Center for Life Science Technologies in Japan, involved
more than 250 scientists across 20 countries and regions.

"Humans are complex multicellular organisms composed of at
least 400 distinct cell types. This beautiful diversity of cell
types allow us to see, think, hear, move and fight infection -
yet all of this is encoded in the same genome," said Alistair
Forrest, scientific coordinator of FANTOM5.

He explained that the difference between cell types comes
down to which parts of the genome they use - for instance, brain
cells use different genes than liver cells, and therefore work
very differently.

"In FANTOM5, we have for the first time systematically
investigated exactly what genes are used in virtually all cell
types across the human body, and the regions which determine
where the genes are read from the genome," he said.

The researchers studied the largest ever set of cell types
and tissues from humans and mice so that they could identify the
location of switches within the genome that turn individual
genes on or off.

They also mapped where and when the switches are active in
different cell types and how they interact with each other.

David Hume, director of the Roslin Institute at Britain's
Edinburgh University and one of the lead researchers on the
project, used the analogy of an airplane: "We have made a leap
in understanding the function of all of the parts. And we have
gone well beyond that - to understanding how they are connected
and control the structures that enable flight," he said.

Although there are many years' more research ahead,
researchers hope the FANTOM5 work will be a reference atlas to
help them navigate the genome and figure out which genes are
involved, and how, in a whole range of diseases: from cancer, to
diabetes, to blood diseases, to psychiatric conditions.

In a linked study, a Roslin Institute team used information
from the atlas to investigate the regulation of an important set
of genes required to build muscle and bone.

Another study used the FANTOM5 atlas to look at the
regulation of genes in cells of the blood, producing what
scientists described as a roadmap of blood cells that will help
them pinpoint where and how cancerous tumors start to grow.

"Now that we have these incredibly detailed pictures of each
of these cell types, we can now work backwards to compare cancer
cells to the cells they came from originally to better
understand what may have triggered the cells to malfunction, so
we will be better equipped to develop new and more effective
therapies," said Forrest.